I looks like an under-cover cop is giving Taylor Swift a sobriety test but there’s a simple explanation as it turns out.
The problem was that the paparazzi were spoiling her enjoyment of the great outdoors. Taylor writes, “I saw the guy with the camera and wasn’t in the mood, so I hiked the whole trail backwards and my security told me when to make turns.” 
And for a little levity, she added an animated gif of the scene in Bridesmaids where Kristen Wiig asks, “If I was drunk, would I be able to do this?”
See the gif and read more here.